Conventional large ships are generally monohull, with the single hull consisting basically of a bow or forward section, a main or midships section, and a rear or stern section. Propulsion is generally by one or more propellers situated behind or under the stern section, turned by shafts rotated by engines conveniently situated at the bottom of the ship, usually near the stern section in cargo ships and towards midships in passenger and other ships. Steerage is accomplished by one or more large rudders situated behind the propellers, with incorporation in some ships of thrust chambers containing propellers or pumps situated across the beam in the forward and/or aft sections of a ship, and powered by separate motors or engines, for maneuvering the ship in harbors and other restricted areas. The forces involved in propelling and steering many large conventional ships do not permit gears for the reversal of the rotation of propeller shafts and/or require a lengthy period of time to accomplish reversal of rotation by gears or reversal of engine rotation. Without bow and/or stern thrusters, reliance by conventional ships on rudders and engine controls may become hazardous under certain circumstances (i.e., a ship proceeding downstream during periods of swift currents when there are speed and maneuvering restrictions in river ports and other restricted areas).
The bow sections of conventional ships are generally in the form of a wedge which divides the water as equally as possible along a central line of the bow to displace the water down and along the sides. In doing so, displaced water is added to other water forward of the bows, creating a mound, or "hill", requiring additional energy to surmount. The mound of water basically remains at the bow until the excess water travels away from the ship in the form of waves, or "wakes." Increasing the speed of a conventional ship increases the volume of water displaced by the bows in a given period of time which increases mounding, and also has the effect of reducing the volume of water at the midsections of the ship, with a resulting mounding of water along the rear portions of the midsections and at the stern. Due to the need to reduce friction on the bows and the area of forward mounded water, conventional ships are generally constructed with a smaller beam to length ratio, with constraints on length resulting from torsion and other forces on structural materials requiring deeper drafts of hulls to increase cargo and other capacities.
The limitations imposed by the water displacement process of conventional ships, requiring increasing factors of power for smaller increments of increased speed, and/or requiring reductions of speed to conserve fuel or lessen hazards by its wakes to other ships and marine equipment, shores and shore installations, has resulted in a number of concepts and designs. To minimize displacement of water at increased speed, marine craft have been designed for many years to lift a hull higher in the water, and more recent power sources have permitted hulls to have minimum displacement by "planing" and/or use of entrapped forced air to lift the hull above the water (i.e., hovercraft). Power and construction requirements limit the size and/or carrying capacity of such marine craft.
Other designs use multihulls, with two or more long narrow hulls reducing the displacement of water, again increasing speed but with diminished load capacities. More recently there has been the concept of a monohull fast ship by producing a high pressure area at the bottom portion of the stern. U.S. Pat. No. 5,832,856 (Giles).
Many years ago there were concepts for modifications of the designs of ships by incorporating one or more tubes from bows to stern with propellers situated both within and outside of the forward and rear ends of the tubes. U.S. Pat. Nos. 14,589 (Arnold); 815,270 (Davids); 1,161,453 (Court). While those earlier concepts had merit, they were based on then existing technologies, materials and ship designs, without systematic development of an integrated ship propulsion and steerage design, requiring total evolution of concepts and design of ships to maximize the benefits of reduction of the energy necessary to displace water and use of the energy of the displaced water in the propulsion and steerage of a ship. In addition, the development of turbine thrusters or "pumps" significantly enhance the propulsion of water when contained and operated in thrust chambers, compared to enhanced conventional propellers.
There is thus a need for a ship propulsion and steering system for reducing water mounding along and under a bow and hull of a mono-hull ship, thereby enhancing displacement of water by the hull permitting increase of the beam to length ratio of a ship and enhancing the steering maneuvering of a ship, according to the following objectives and description.